1. Field of the Invention
This invention relates generally to lawn mowers and, further, lawn mowers with a grass striping mechanism used to impart distinctive patterns on lawns and sports playing fields.
2. Description of Related Art
In the area of lawn and sports playing field maintenance, grass striping is a common practice, generally used in combination with cutting grass, whereby the grass on a lawn or field is bent in a particular direction causing light to be reflected therefrom in order to achieve an aesthetically pleasing appearance. Typically, grass striping is accomplished through the use of rollers. In commercial lawn mower units having front and rear tires and a mower deck having one or more mower blades rotatably disposed therein, such rollers are typically fixedly attached to the commercial lawn mower either at the rear of the mower deck or at the rear end of the mower vehicle body as disclosed in U.S. Pat. Application Publication No. 2005/0066642 to Sugden et al. Striping rollers may also be associated with residential push mowers and are typically attached to the rear end of the mower deck of the mower, as disclosed in U.S. Pat. No. 6,523,335 to Vanderipe and U.S. Pat. No. 5,870,888 to Pugh. The rollers in commercial lawn mowers which are disposed at the rearward end of the mower deck allow the newly cut grass to be immediately bent in a particular direction. Whatever the roller location, after the mower blade(s) cuts the grass, the roller bends the grass in the same direction that the roller is moving. With each pass along the lawn or field, the roller stripes the grass in a band having a width equal to that of the roller. It is noted that, in general, striping rollers provided on lawn mowers, whether of commercial or residential varieties, have traditionally been fixedly attached to the rear end of the mower deck as disclosed in U.S. Pat. No. 6,047,530 to Bednar and U.S. Pat. Nos. 7,086,215 and 6,928,798 to Hensley et al. In addition, such rollers are often mounted to the mower deck in a static position above the ground in order to provide ground clearance and accommodate the contours of the lawn or field being mowed. Consequently, the rollers, in these prior art mechanism, do not sit directly on the grass and the resultant bend imparted thereto is often minimal and insufficient to obtain the desired visual effect.
Typical striping mechanisms often have heavy rollers that are, as indicated, rigidly fixed or mounted to the mower or cutting deck to ensure that sufficient downward force is applied to produce the desired striping effect. However, such heavy, full-width rollers may inadvertently, and often do, strike ground surfaces or obstacles during operation, resulting in potential damage to the lawn surface and/or the roller. Accordingly, current striping mechanisms generally lack adjustability and, in operation, typically apply their full force or weight to the grass regardless of particular grass and ground conditions. In order to change the applied downward pressure of the striping roller complete removal or loosening and repositioning of the mechanism is often required, typically with the use of hand tools. To overcome such disadvantages, some striping mechanisms replace the heavy striper roller with a rubber wiper member as disclosed in U.S. Pat. No. 7,024,845 to Kallevig or use a brush striper member as disclosed in U.S. Pat. No. 6,832,468 to Weinlader. In order to overcome weight and rigidity problems associated conventional one-piece striper rollers, some inventors have proposed using multiple rollers individually mounted on a shaft as a replacement to a one-piece striper roller as disclosed in U.S. Pat. Nos. 6,962,039 and 6,993,894 to Greenhoe.
A recent advance in riding mowers relates to commercial and residential lawn mowers that incorporate a turning feature or a zero-turning radius, whereby, upon turning, the inner tire on the inside of the turn radius rotates backward while the outer tire on the outside of the turning radius rotates forward. However, upon turning, a striper roller fixedly disposed between the mower deck and the rear tires in such a vehicle is forced to travel in a direction perpendicular to its axis of rotation. As a result, the striper roller often becomes wedged in the grass, thereby inhibiting the lawn mower from preventing the turn. Accordingly, it has been particularly technically challenging to provide a striper mechanism that is suitable for use on such “zero-turn” mowers.